CD8A and cholangiocarcinoma: Additionally, we utilized transcriptomic data from CCA and HCC patients in the TCGA database to classify patients into high- and low-level groups on the basis of the signature genes of each T-cell subtype, namely, CD8+ T cells (CD8+ T cells (CD8), Trm (CD8, CD69, GZMB), and Tstem (CD8, TCF7), and conducted survival analysis.